Robust Tattoo Electrode Prepared by Paper-Assisted Water Transfer Printing for Wearable Health Monitoring

Long-term and stable monitoring of bioelectrical signals represented by electrocardiogram (ECG) has a great application value for wearable electronics. The ECG monitoring require low-cost, flexible and robust electrical system that can work throughout daily activities. In this article, we propose a paper-assisted strategy to fabricate a tattoo ECG electrode based on the low-cost water transfer printing technology. Similar to the tattoo attached on the skin, the fabricated electrode allows complying with the skin deformation comfortably and accommodating the local strains. The ECG signals collected by the tattoo electrode have a high signal to noise ratio, robustness, mechanical stability and strong immunity to motion artifact even under the severe deformation of skin. The tattoo electrode enables convenient and long-period ECG monitoring during various activities, including exercising, sweating, rubbing, and flushing. As a proof-of-concept, a soft wireless ECG system is developed by integrating with the tattoo electrode, commercialized IC chips, and a low-energy Bluetooth module to achieve the functions of signal acquisition, data processing and communication. The measured results show that the proposed strategy has a promising application for wearable health monitoring system.